A motor control device of a hybrid electric vehicle and/or an electric vehicle according to the related art drives a vehicle or various types of electronic devices within the vehicle by controlling a driving motor installed in the vehicle. The motor control device obtains a variety of information, such as a current flowing in a motor or a rotor location, from various types of sensors such as a current sensor and a location sensor, and uses the obtained variety of information to control the motor.
The motor control device uses an inverter to control torque of the driving motor. This inverter operates in response to an instruction received from an upper controller and controls the driving motor by converting a direct current (DC) voltage of a battery to a variable alternating current (AC) voltage through pulse width modulation (PWM) control.
When excessive torque occurs in the motor of which the torque is controlled by the inverter, the stability of a vehicle system may be significantly degraded.
Currently, to improve the stability of the system to meet the expectations of a full system of a vehicle, software for a fail safe function is embedded within an electronic control unit (ECU). Fail safe software is applied even to the inverter to improve the stability of the driving motor.
However, when the fail safe software of the inverter is not executed due to a software defect or an operational defect within the ECU, for example, a memory error, a malfunction of the inverter is not detected even while the inverter is in an abnormal state, which has caused the driving motor controlled by the inverter in the abnormal state not to be properly operated.
Accordingly, there is a need to improve the stability of a motor control device by appropriately monitoring whether fail safe software of an inverter applied to a motor control device of a hybrid electric vehicle and/or an electric vehicle normally operates.